BIOS 242 EXAM 3 ESSENTIAL STUDY
QUESTIONS AND ANSWERS
◉ Phagocytosis.
Answer: A multistep process carried out by neutrophils, eosinophils,
macrophages, and dendritic cells to destroy microbes. The steps of
phagocytosis include chemotaxis, adhesion, engulfment, phagosome
formation, phagolysosome formation, killing, and release of residual
debris.
◉ Interferon.
Answer: When a cell becomes infected by a virus, it will start
producing and releasing the protein, interferon, which binds to
receptors on nearby cells. The binding of interferon to receptors on
these cells causes a series of events that block viral replication.
◉ Complement system.
Answer: The complement system destroys bacteria, cells, and
enveloped viruses. It can be activated by antibodies or by two other
pathways known as the lectin and alternative pathways. The
outcomes of activation of the complement pathways are
inflammation, phagocytosis, and the formation of membrane attack
complexes (MAC).
, ◉ Characteristics of specific immunity.
Answer: Specificity, diversity, inducibility, clonality, tolerance, and
memory.
◉ Antigen.
Answer: Cells, chemicals, or particles that activate B-cells or T-cells
and stimulate resistance to an infection.
◉ Epitope.
Answer: The region on an antigen to which an antibody binds.
◉ Hapten.
Answer: Small molecules, such as drugs and metals, which cannot
elicit an immune response by themselves but once attached to a
larger carrier molecule (usually a protein), can trigger an immune
response.
◉ Events of T-cell development.
Answer: The lymphocyte originates in the red bone marrow and
then travels to the thymus for maturation.
◉ Events of T-cell activation.
Answer: A phagocytic cell processes an antigen and displays an
antigen complex on its surface. The cell presents the antigen
QUESTIONS AND ANSWERS
◉ Phagocytosis.
Answer: A multistep process carried out by neutrophils, eosinophils,
macrophages, and dendritic cells to destroy microbes. The steps of
phagocytosis include chemotaxis, adhesion, engulfment, phagosome
formation, phagolysosome formation, killing, and release of residual
debris.
◉ Interferon.
Answer: When a cell becomes infected by a virus, it will start
producing and releasing the protein, interferon, which binds to
receptors on nearby cells. The binding of interferon to receptors on
these cells causes a series of events that block viral replication.
◉ Complement system.
Answer: The complement system destroys bacteria, cells, and
enveloped viruses. It can be activated by antibodies or by two other
pathways known as the lectin and alternative pathways. The
outcomes of activation of the complement pathways are
inflammation, phagocytosis, and the formation of membrane attack
complexes (MAC).
, ◉ Characteristics of specific immunity.
Answer: Specificity, diversity, inducibility, clonality, tolerance, and
memory.
◉ Antigen.
Answer: Cells, chemicals, or particles that activate B-cells or T-cells
and stimulate resistance to an infection.
◉ Epitope.
Answer: The region on an antigen to which an antibody binds.
◉ Hapten.
Answer: Small molecules, such as drugs and metals, which cannot
elicit an immune response by themselves but once attached to a
larger carrier molecule (usually a protein), can trigger an immune
response.
◉ Events of T-cell development.
Answer: The lymphocyte originates in the red bone marrow and
then travels to the thymus for maturation.
◉ Events of T-cell activation.
Answer: A phagocytic cell processes an antigen and displays an
antigen complex on its surface. The cell presents the antigen
